Laparoscopy is the operative procedure that allows the surgeon to view the abdominal cavity with a long rod-type scope (Laparoscope), to perform operations without the need of employing large incisions. The Laparoscope is inserted through a small incision around the navel. Before the Laparoscope can be inserted, the abdominal cavity has to be insufflated with CO2 to allow the introduction of a large trocar (the Principal Trocar-Cannula Unit) which provides the portal for the introduction of the Laparoscope. To accomplish this initial phase of this procedure, to create a pneumo-peritoneum, the surgeon inserts in or around the navel a Veress needle. This is a rigid, metallic needle, of ten, twelve, fifteen or seventeen cm of length, and two mm in diameter. This needle is pushed through the anterior abdominal wall until it is several centimeters inside the abdominal cavity. If the needle is successfully placed into the free space of the abdominal cavity the process of insufflation proceeds uneventfully.
In order to ascertain that the Veress needle is inside the abdominal cavity, surgeons “test” the position of the needle employing various maneuvers. There are several such tests. One is “manometer test”, which involves the connection of the Veress needle to the insufflating system and by pulling up the anterior abdominal wall with towel clips the operator observes if a negative pressure is registered in the system's manometer. Another maneuver is the “hanging drop test”, which consists of placing water at the upper end of the Veress needle and seeing if the drop of water is sucked inside the needle by the vacuum in the abdominal cavity. A third test is the “hissing sound test”, in which the operator turns the valve in the Veress needle to the off position and then opens it. He then lifts the anterior abdominal wall with towel clips to suck air from the needle into the abdominal cavity. He is supposed to hear the hissing sound of the air going inside the needle. Another test is injecting air inside the Veress needle with a syringe to see if it goes easy. An easy injection means the needle is in the abdominal cavity. Another test is the injection of a small amount of water. In this maneuver, the surgeon first aspirates the needle with a syringe. If no blood or bowel content is obtained, the surgeon then injects a small amount of sterile water and aspirates again. If the water is re-aspirated, it means that the operator is in an enclosed space, not the free space of the abdominal cavity. One more maneuver is the “double-click test”. In this test, the operator should hear two distinct clicks as the needle traverses critical layers of the anterior abdominal wall. If this double-click is heard, it is reassuring that the needle is in the abdominal cavity. The most sensitive of all tests seems to be the detection of a high insufflating pressure in the laparoscopy system. Modern equipment is good in detecting unusually high pressure when the needle is not in the right place but even this last test is not free of frequent errors. This high-pressure indicator is not reliable and the creation of subcutaneous emphysema or pnemo-omentum may still occur in spite of a seemingly low pressure in the system.
Very often all of these testing maneuvers eventually fool the operator into believing that he or she is in the right place when, indeed, the needle is not in the free-space of the abdominal cavity but in the thickness of the anterior abdominal wall or hitting an intra-abdominal structure. None of these maneuvers guarantee successful access to the free space of the abdominal cavity. If insufflation is done when the Veress needle is within the thickness of the anterior abdominal wall, a subcutaneous emphysema is then created and, if not recognized immediately, it becomes of a significant size and subsequent attempts to inflate the abdominal cavity become increasingly more difficult.
After the insertion of the Veress needle, the initiation of the insufflation is started. Surgeons usually begin to inflate with a low flow of CO2. After a wait of a few seconds the surgeon sees if the characteristic tympanic sound is heard on percussion of the abdomen, generally on all four quadrants of the anterior abdominal wall. During this waiting period he also perceives with his hand the typical drum-like resilience of the anterior abdominal wall on percussion when the cavity is filled with gas. The operator then proceeds to continue the insufflation at a high gas flow. The fact remains that before accurate abdominal insufflation is achieved, there is a good degree of anxiety created by the doubt, hesitancy, uncertainty and fear of failure that assails the surgeon because he is not absolutely sure that the tip of the needle is in the right place. This doubt prompts him to remove and re-insert the Veress needle until he is “reasonably” sure he is in the right space to cautiously let the insufflation begin.
To this day, the creation of unwanted subcutaneous emphysema remains a problem in Laparoscopic procedures. The more obese the patient is, the greater the chances of its occurrence. Besides the above-mentioned drawbacks, there are other complications associated with the Veress needle. One is the creation of pneumo-omentum, which is the instillation of CO2 into the thickness of the omental flaps. Another complication is the accidental puncture of intestines or the injury to blood vessels. Because the Veress needle has to be inserted several centimeters inside the abdominal wall, if the patient is thin, the risk of accidental puncture of a major blood vessel is greatly increased. All textbooks of laparoscopy warn surgeons about the exceedingly close proximity of the anterior abdominal wall to the major vessels in these thin patients, particularly at the level of the navel, the site of insertion of the Veress needle.
In an effort to overcome these series of obstacles associated with the trans-abdominal insertion of the Veress needle, surgeons all over the world have tried other ways to access the abdominal cavity with the Veress needle. In obese patients they insert the Veress needle trans-vaginally to reach the cul-de-sac, or even directly through the fundus of the uterus. In some countries, the gas-less Laparoscopy has been introduced.
Various modifications to the Veress needle have been invented. One is the Veress-Frangenheim needle, which is double-barreled to permit insufflation while at the same time measure the pressure around the needle. Another is the Foures-Kuss needle, which has lateral holes that permit insufflation even if the needle tip is hitting an obstacle. None of these varieties is now in use, and furthermore, they are subject to the same failure of creating subcutaneous emphysema or injury to internal organs as the original Veress needle.
To avoid all the problems associated with the use of the Veress needle, Harrit Hasson in 1972 introduced the Open Laparoscopy. In this alternative, the Veress needle is entirely avoided and, instead, the abdominal cavity is entered in the traditional way via a small incision below the navel to allow the insertion of the trocar carrying the portal to the Laparoscope. Currently, however, the Veress needle is, by far, the preferred method being used but it is, unfortunately, not devoid of its attendant risk of failure due to misplacement of the needle in the thickness of the anterior abdominal wall or potential injury to internal structures.
The present invention solves easily, safely, quickly, and error-free, all the problems associated with the use of the Veress needle for abdominal insufflation for Laparoscopy, namely, the creation of subcutaneous emphysema or pneumo-omentum, and the risk of injury to intra-abdominal structures. If a safe and effective pneumo-peritoneum can be created by the invention, there is no need for open Laparoscopies.
Insertion of the large Principal Trocar-Cannula unit, once the abdomen is successfully inflated, is not devoid of difficulties and complications. These Principal Trocar-Cannula units have either sharp blades or sharp points at their tips. Insertion has to be done by forcibly pushing them through the anterior abdominal wall. It is literally a blind thrust of this unit well inside the abdominal cavity. Sometimes the insertion is difficult due to resistant abdominal walls, or it may go too fast inside the abdomen. It is a known fact that the force applied for the insertion has to be greater than the resistance of the inflated abdominal wall. Although complications with the insertion of the Principal Trocar-Cannula unit are significantly rare, when they occur they tend to be very serious.